Mc60 mqtt and ssl error

IoT Modules GSM Module
1

AT+QMTOPEN=0,“test.mosquitto.org”,1883

OK

+QMTOPEN: 0,0

+QMTSTAT: 0,1
AT+QMTPUB=0,1,1,0,“dev/dev-storm/log”,“abcd”

+CME ERROR: 3518
I can’t understand why showing me CME error. Please suggest any solution
My MC60 FW: ATI

Quectel_Ltd
Quectel_MC60
Revision: MC60CAR01A15

2

After we open the network by AT+QMTOPEN, we then use AT+QMTCONN to connect to server before using AT+QMTPUB to declare the message topic …